In the practice of human and veterinary medicine, it is often desirable and necessary to use various polymeric devices such as urinary catheters, cerebro peritoneal shunts, breast implants, artificial joints, hemodialysis devices and the like to treat or diagnose disease. Such devices are often contaminated by bacteria, fungus, viruses and other organisms or infective proteins, resulting in systemic and/or local infection. Such contaminants sometimes lead to sepsis and death. This phenomenon is further aggravated by contact of the device, such as urinary tract Foley type catheters, for example, by external mammalian tissues, such as skin or mucous membranes which themselves are carriers of potentially infective organisms.
Various proposals have been made in the past to provide protection for such devices such as catheters and various bacteriostats and bactericides have been applied to the surfaces of urinary catheters to prevent infection. However, none of these have been completely effective and the danger of infection and the potentially fatal problems it presents is always present, particularly in the case of indwelling catheters such as urinary tract Foley type catheters.
It has also been believed that therapeutic risk involved with the use of medical devices could be controlled, eliminated or attenuated if the device itself had antiseptic properties. Medical use and research has demonstrated that antibiotic use alone such as systemic treatment separate from local application to the device, is ineffective for long term antisepsis due to bacterial resistance and sometimes drug allergic reaction. Therefore, the use of an antiseptic agent whose anti-infective organism-effects are multi focal and wide-spectra is necessary if long term and safe anti-sepsis is to be imported to the device. It has become readily apparent that many agents, while not developing microorganism resistance, have a limited spectrum such as nitrofurazone and chloroxylenol, which are weakly effective against Pseudomonas and some Proteus, silver sulfadiazine, which is weakly effective against Staphylococcus aureus and Pseudomonas, and mandelic acid, which is weakly effective against Proteus. It has accordingly not been possible to achieve reliable long term indwelling of urinary catheters capable of effective antiseptic action.
This problem has been especially prevalent in urinary retention catheters such as Foley catheters. Retention catheters connect the patient's bladder to the meatus of the patient to continuously remove urine from the patient's bladder. Sources of urinary retention catheter related urinary tract infections are suspected to be bacteria progressing from the patient's meatus through the peri-urethral space into the bladder or the catheter lumen. A number of methods and devices in the prior art for attempting to prevent bacterial caused urinary tract infections are disclosed. Examples include U.S. Pat. Nos. 4,773,901; 5,098,379; 5,236,422; 5,261,896; 5,269,755 and 5,269,770. However, for many applications, these devices have not proved to be totally effective. As a result, a substantial probability of acquiring a urinary tract infection still exists when using these devices.